Why We Moved From Microservices Back to a Modular Monolith

In 2023, Flowdesk's backend was 47 microservices across 12 teams. Today, it's a single modular monolith. This is the story of why we went back — and why we're faster than ever.

The Microservices Tax

On paper, our microservices architecture was textbook. Bounded contexts, API contracts, independent deployments. In practice, the operational overhead was crushing.

Every feature required coordinating across 3-5 services. Debugging meant tracing requests across multiple systems. A simple schema change could cascade into weeks of coordinated deploys. Our incident rate was climbing, and developer satisfaction was falling.

The Decision

We didn't make this choice lightly. We spent three months measuring the actual costs: developer time spent on infrastructure vs. product work, incident frequency, mean time to recovery, and feature velocity. The data was clear — we were spending more time managing the architecture than building features.

The Migration

We migrated incrementally over six months. Each service was folded into the monolith as a well-defined module with clear boundaries. We kept the good parts of microservices — clear domain ownership, API contracts between modules, independent testing — without the distributed systems overhead.

The Results

Deploy frequency: From 4 deploys/week to 15 deploys/day. No more cross-service coordination.

Incident rate: Down 60%. Most incidents were caused by service-to-service communication failures that no longer exist.

Developer onboarding: New engineers ship their first feature in 3 days instead of 2 weeks.

Latency: 35% reduction. Turns out, network hops between services add up.

When Microservices Make Sense

We're not saying microservices are always wrong. They make sense when you have truly independent teams, wildly different scaling requirements, or genuine isolation needs. For most products at our scale, a well-structured monolith is the better choice.